THE USE OF METHYL JASMONATE TO EXTEND SHELF LIFE AND REDUCE MICROBIAL CONTAMINATION OF FRESH-CUT CELERY AND PEPPERS

Authors: Buta, Joseph - George; Moline, Harold

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/26/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The fresh-cut industry is a rapidly growing segment of the fresh fruit and vegetable industry. Maintaining quality of fresh-cut produce for institutional and salad bar sales as well as to individual consumers is a major concern of the industry. Postharvest losses are severely limiting the expansion of the sale of fresh-cut produce. A rising consumer demand for fresh-cut produce and public concern over pesticide residues has led us to explore new methods to extend shelf life and reduce decay. Decay and physiological breakdown severely limit the shelf life of fresh-cut celery and peppers. We are studying the treatment of fresh-cut celery and peppers with methyl jasmonate, a naturally occurring compound, as a method to reduce postharvest deterioration and extend storage life. This study shows that methyl jasmonate can decrease the rate of deterioration of treated fresh-cut segments by apparently enhancing natural resistance to microbial decay. The resulting changes may help retain quality of fresh-cut celery and peppers in the market. The treatments may be a strategy we can implement to reduce our reliance on pesticides while maintaining produce quality.

Technical Abstract: While studying the effects of methyl jasmonate on chilling injury, a decrease in the rate of deterioration of treated fresh-cut segments was noticed, along with an apparent decrease in microbial growth. This study showed that methyl jasmonate vapor from a 10-4 or 10-5 mol source in a 1L container retarded deterioration of celery sticks for 2 weeks at 10 degrees C. The number of bacterial colonies was reduced to 1/1,000 of control after 1 week of storage. A methyl jasmonate emulsion at 10-4 or 10-5 mol/L retarded deterioration of green pepper strips for 2 weeks at 10 degrees C. The number of bacterial colonies was reduced to 1/1,000 of control also after 1 week of storage and, in particular, the appearance of soft rot was retarded by the jasmonate treatment. Measurement of the amount of methyl jasmonate vaporized during storage was done by use of an 3H-jasmonate internal standard. Less than 1x10-6 mole methyl jasmonate vapor had caused the biochemical changes in the stored vegetables resulting in prolonged storage life and decreased microbial growth.